Trying to track down a payment

I am trying to track down a payment for a product that I never received, the payment was made a few months ago and I don't have my statement, was wondering if it is possible to find that out by looking at the site or its source code so I can contact them?

If you have a dispute with the site (such as you didn't receive the product), you need to contact the store/site owner. Start with the order-confirmation email you received when you made the purchase. Also use the site's "contact-us" page.
If you can't reach them, then also contact their hosting service.
You might find http://www.domaintools.com or http://who.godaddy.com to be useful for looking up additional contact information, using the website address for the store you purchased from.

If you used a credit card and feel that you have been ripped off, we would suggest that you contact your credit card company/bank and request a chargeback (refund) for not getting your merchandise. They'll go back to the seller and that'll get the seller's attention.

If you think they have committed fraud, then you should also report the site to your local authorities.

Thanks DrByte. I will do all of that, I am still interested to know if there is a way of telling which module is being used for the payment gateway.

If you go back to the store, add an item to your cart and then start the checkout process. When you get to the checkout_payment page, you'll want to "View Source" (usually Ctrl+U). The payment module's "code" forms part of the HTML id attribute for associated fields.

Regarding receipt: is/was the product digital in nature or something to be sent by mail/post?

Brilliant, thanks lat9. mc12345678 - this is postal.